22 Temmuz 2016 Cuma

HOW TO MAKE YOUR POWER SUPPLY

                                 POWER SUPPLY

Materials: 

  1. Cockcroft-Walton Generator: https://engineersandscientists.blogspot.com.tr/2016/05/cockcroft-walton-genereator.html
  2. Box
  3. DC Plugs
  4. Silicon Gun
  5. Silicon
  6. Soldering iron
  7. Solder
  8. Cable

   We put the Cockcroft-Walton Generator in to a box that we bought to keep it safe. Then from the ends of every stages we added plugs. 


Back side of power supply






Front side of power supply

Upside of power supply











5 Mayıs 2016 Perşembe

COCKCROFT WALTON GENEREATOR

                           Cockcroft-Walton Generator

     This experiment will be carried out to reach very high voltages from typical city source. There is a very cheap method called Cockcroft-Walton Generator to reach almost 6 kiloVolts. We need this high voltage difference because our real aim is to make a Cathod-ray Tube.
   
     Ideas of making theese experiments are given by Prof. Dr. Serkant Ali Çetin and Associate Prof. Veysi Erkcan Özcan.

     Then Prof. Dr. Doğan Güneş has found an available laboratory for us.



     22.04.2016


     Firstly, we started with 1 stage Cockcroft-Walton circuit to be sure about our idea of circuit.


Design with breadboard.


Then we realised that breadboard may cause some problems such as burning because of high voltage. And take out of the breadboard and connect them with the cable band.


2 stages Cockcroft-Walton circuit


     After being sure about our circuit, we connect it to the 10 Volts AC 50 Hertz source and we measure the output 26.6 Volts DC. As it is known we should have measured very nearly 30 Volts DC We checked our circuit one more time and realised that one diode is connected throuhg the wrong way. We turned it reverse and connected it to the same input Voltage Source. This time we measured 31 DC voltage.  We connected it to the small input before connect it to the city source, othervise it would have more risky.

     Those attempts were just for checking the connections of our circuit. The aim of this experiment is to reach very high DC voltages like 5000 Volts for making Cathode-Ray Tube. That's why we connected 1 stage circuit. We connected it to the city source which is 220 AC 50 Hertz Voltage. But first capacitor burned in nearly a seconds.




02.05.2016

     Firstly, we used 1 uF 450 volt electrolytic capacitor and 1000 Volt diode for 1 stage Cockcroft Walton curcuit. But this time, we add 50 kohm resistance and give 220 AC 50 Hertz voltage and we got 175 Volts DC output.

Design with jumpers

     After some research, we decided to change our capcitors from electrolytic capacitor to the film capacitor.
     Then we used 100 nanoFarad 630 volt Film Capacitor and 1000 Volt diode for 1 stage Cockcroft-Walton circuit. We took off resistance because we did not need to decrease the current. And our output became 220 AC 50 Hertz Voltage and we measured 489 Volts DC.


05.05.2016

     Firstly, we made a circiut of 3 stages Cockcroft-Walton Generator circuit with the new capacitors diodes. when we made this circuit we didn't soldered it together. After discussing further, we decided that it would for the best if we soldered the circuit together. Then we added a home-made high voltage probe to multimeter so that we could see the value of volt we got. Our input was 220 volts AC, 50 Hz voltage,our output is 1250 Volts DC for now.


Home-made High Voltage Probe:

     To making this device we took 9 more resistors which are same with multimeter has (1 Mega ohm). We attached the resistors in series so that the quantities of resistors would add up and with multimeters own resistance and we obtained the total of 10 mega ohm's resistor. With this device, we became able to see high voltage values in multimeter. If you want to have more information about home-made high voltage probe, you can access the link here: https://www.youtube.com/watch?v=RAOw0mHQRvk

The resistances that we add into our multimeter

     Then we added 1 more stage and our output became 940 Volts DC. When we made it 5 stage Cockcroft Walton Generator circuit we ended up with 930 Volts DC. After these results, we measured every single capacitors' voltages stored.

5 stages Cockcroft-Walton circuit

     After discussing, we decided to put diodes which are paralel to the other diodes starting from the 4th stage. First we added 2 paralel diodes at 4th stage. The result was 940 Volts DC. It became 1220 Volts DC . We thought that adding these paralel diodes acted as some sort of capacitors own their own, thats why the value has increased. Then we added 5th stage with 2 paralel diodes. Normally we had 930 Volts DC in the end of 5th stage,  it became 1060 Volts DC.

The circuit with 2 paralell diodes

We took out the fifth stage and we added 2 more paralel diodes to fourth stage which means in fourth stage we had 3 paralel diodes as you see below. And we measured the output 1220-1230 Volts DC.

The circuit with 3 paralell diodes

After these results we decided to take the extra ones out and instead of paralel, we would put them in series with the original diodes. The result was 400 Volts DC. It decreased by a lot.

The circuit with series diodes
















09.05.2016

We tested different circuits as shown below.
-2 diodes which are parallel to each other with 5 stages---1040 V




  • 2 diodes and 2 capacitors which are parallel to each other with 5 stages----1540 DC Volt





  • 2 diodes and 3 capacitors which are parallel to each other with 5 stages----1880 DC Volt.



  • Last two stages has 3 diodes and 3 capacitors which are parallel to each other with a total of 5 stages----1330 DC Volt


13.05.2016



  • After these results we decided to change our diodes and capacitors. We got diodes which have maximum voltage break is 1500 volts. And we got capacitors which have 1uF capacitance.




  • For being unstressed, we also got CRT Flyback transformer which generates high voltages. They are used to be in old televisions. And when some of us was trying to find solution to the Cockcroft-Walton, some of us was trying to produce a high voltage from CRT Flyback. But it couldn't work. the home-made high voltage probe that we made.


16.05.2016


  • We bought a new multimeter and converted it to the high voltage prob again . And we decided to add transformer to our Cockcrof-Walton circuit. Because some previous analysis, we realised that, with 220 AC input volltage there will be a output limit which is nearly 1800 volts. 


The analysis of the circuit with 220 AC input (from LTspice IV)


After some more analysis, we decided to add a transformer which will give us 630 AC voltage as input.

20.05.2016


  •       First we tested our old circuit(3 paralel capacitors(0.1 uF, 630 V) , 2 paralel diodes(1000 V)) with transformer and we measured 2050 DC Volt as output. 

  • Then we tested our new circuit(capacitor 1 uF 630 V, diode 1500 V)  with transformer and we measured 6300 DC Volt as output for a second then it  exponantial decreased. We don' t now the reason yet. We think that one of the capacitors burnt. So we will check the stages one by one until we find the burnt one. 



  •    We understood that the problem is after second stage because after that stage the voltage difference was not changing. One of the components after that stage is fried.



  •     Then we came back our old circuit(3 paralel capacitors(0.1 uF, 630 V), 2 paralel diodes(1000 V)) and change its diodes, we added 1500 V diodes. Firstly, we made 3 stages and mesaured 3350 V. Then we added 2 more stages on to them and we measured 3850 V for 3 seconds then the capacitors exploded starting from the first one.



 

24.05.2016

    After the last test which is ended by little explosions, we considered that we need more powerfull capacitors which will be able to carry much more voltages. We found 1 uF 1000 Volts capacitors and 1500 Volts diodes. So we made 5 stages Cockcroft-Walton circuit with those circuit elements. And we reached 8350 Volts!  
THE VICTORY!

Thanks to Prof. Dr. Serkant Ali Çetin, Associate Prof. Veysi Erkcan and Prof. Dr. Doğan Güneş for their helps.

In a short time, we will record an experiment video about this experiment! And you will be able to reach it from our youtube channel!

THANK YOU FOR YOUR INTEREST! :)